The Calogero--Moser Derivative Nonlinear Schrödinger Equation (2208.04105v2)

Abstract: We study the Calogero--Moser derivative NLS equation $$ i \partial_t u +\partial_{xx} u + (D+|D|)(|u|^2) u =0 $$ posed on the Hardy-Sobolev space $H^s_+(\mathbb{R})$ with suitable $s>0$. By using a Lax pair structure for this $L^2$-critical equation, we prove global well-posedness for $s \geq 1$ and initial data with sub-critical or critical $L^2$-mass $| u_0 |{L^2}^2 \leq 2 \pi$. Moreover, we prove uniqueness of ground states and also classify all traveling solitary waves. Finally, we study in detail the class of multi-soliton solutions $u(t)$ and we prove that they exhibit energy cascades in the following strong sense such that $|u(t)|{H^s} \sim_s |t|^{2s}$ as $t \to \pm \infty$ for every $s > 0$. \end{abstract}